A plurality of semiconductor elements formed on a semiconductor substrate such as a wafer is divided into a plurality of semiconductor chips by dicing along dicing regions provided in the semiconductor substrate. In some cases, a semiconductor substrate is, for example, a composite substrate configured with a plurality of different materials like a GaN-based semiconductor layer/silicon substrate/metal film. At the time of dicing the composite substrate, since physical properties of the materials are different, chipping, cracking, and the like of the substrate is likely to occur. Therefore, it is difficult to improve dicing yield of the semiconductor device.